You can resolve this by closing Toad, navigating to your user files folder, deleting all files that start with a ~, and then restart Toad. Your user files location is a subfolder of Toad's application data directory and you can find its path in Toad Options on the General page. It is going to be %APPDATA%\Quest Software\Toad for Oracle\10.6 by default.
If you could be so kind as to zip those files before deleting and send the zip to me offline at michael<dot>staszewski<at>quest.com I'd appreciate it.
Thanks,
Michael